Damper for damping a pivot movement

ABSTRACT

A rotary damper for damping a pivoting motion has two components, one component being an inside component and the other component an outside component. The outside component radially surrounds the inside component at least in sections. Between the components a damping gap is formed that is bordered radially inwardly by the inside component and radially outwardly, by the outside component. The gap is filled with a magnetorheological medium. The damping gap can be exposed to a magnetic field to damp a pivoting motion between the two counter-pivoting components about an axle. One of the components is provided with a plurality of radially extending arms. The arms are equipped with an electric coil having a winding, the winding extending adjacent to the axle and spaced apart from the axle.

The present invention relates to a damper for damping relative motion, the damper comprising a pair of components movable relative to one another and whose relative motion can be damped.

The prior art has disclosed a great variety of dampers for damping relative motions. Translational dampers tend to be employed in which a piston connected with a piston rod subdivides a cylindrical damper chamber into a first chamber and a second chamber. The damping medium flows through a damping duct at or in the damping duct from one of the sides of the damper piston to the other of the sides as a translational relative motion occurs which is being damped.

Translational dampers are suitable for multiple purposes such as for a shock absorber in bicycles or motor vehicles or for damping other shocks. The drawback of these translational dampers is that a considerable amount of damping medium needs to be used since the damping medium must be present other than in the damping duct, also on both sides of the damper piston. Moreover this structure results in a considerable hydraulic basic damping in the flow duct in dependence on the flow rate.

There is increasing desire for inexpensive, controlled dampers allowing to vary the degree of damping during operation for example electrically by means of a control device. The use of magnetorheological mediums and in particular fluids has been tried and tested for damper systems showing particularly fast responses and thus allowing to achieve changes of the damping strength within a few milliseconds. Magnetorheological fluids are comparatively expensive though so that its use is difficult or uneconomic for many applications. It may for example be useful to provide an accelerator pedal or brake pedal in a motor vehicle or a truck with a damper to obtain damped resetting of the pedal concerned. Moreover, damped movement provides enhanced feedback to the driver of such a vehicle. The budget for damping these motor vehicle components is considerably lower than for damping the wheels or the motor vehicle overall. This is why these translational dampers are not suitable for low-cost damper applications.

Devices have been disclosed for clutches and brakes provided for rotative operation. A gap, for example cylindrical, is provided with externally and internally splined laminations for subdividing the cylindrical gap into a number of partial gaps and transmitting the required forces. The drawback is the high structural complexity and the amount of magnetorheological fluid used which increases costs.

WO 2014/037 105 A2 discloses a transmission apparatus using only a minimal amount of magnetorheological medium although the damper operation is translational. This is achieved by way of sealing the axial ends of the damping gap so that the magnetorheological medium remains in the damping gap as a kind of friction lining. Although this transmission apparatus is generally functional it shows the drawback of a comparatively high basic force applied which first needs to be overcome before damping is possible.

It is therefore the object of the present invention to provide a damper for damping a relative motion or/and for generating a tactile feedback, which includes a low-cost structure and requires only a minimal amount of magnetorheological medium and allows enhanced response sensitivity. The damper is in particular intended to be quite simple in structure to thus allow industrial applicability in profitable quantities.

This object is solved by the damper having the features of claim 1. Preferred specific embodiments of the invention are the subjects of the sub claims. Further advantages and features of the present invention can be taken from the general description and the description of the exemplary embodiments.

A damper according to the invention is configured as a rotary damper and serves to damp a pivoting motion. “Damping” may also be understood to mean a tactile feedback ensuing from damping, i.e. a return signal of force/momentum to the user. The rotary damper comprises two components, one of the components comprising an inside component and the other component, an outside component. The outside component radially surrounds the inside component at least in sections. Between the components a damping gap is disposed that is bordered radially inwardly by the inside component and radially outwardly, by the outside component and which is at least partially and in particular at least nearly entirely filled with a magnetorheological medium. The damping gap can be exposed to a magnetic field to damp a pivoting motion between the two contrapivoting components around an axle. The damping gap is preferably annular and circumferential in configuration. At least one of the components is provided with a plurality of at least partially radially extending arms. At least some of the arms are equipped with an electric coil having at least one winding each. The winding and in particular each winding extends preferably completely adjacent to the axle and spaced apart from the axle.

The rotary damper according to the invention has many advantages. A considerable advantage of the inventive rotary damper is a pivoting motion that is employed for damping. This allows to dispense with sealing the components movable relative to one another during a translational relative motion toward one another. It is sufficient to provide between the two components for example a circumferential seal which does not need to move during the relative motion. This achieves a base momentum or base force that is much lower than in translational movement where for example a seal ring must be displaced on an axle while the two components are axially displaced relative to one another.

Providing a plurality of radially extending arms, each provided with an electric coil having at least one winding each, allows to apply an optimal magnetic field on the damping gap between the inside component and the outside component. The available surface and the volume of the damping gap are utilized optimally so that a narrow and in particular circumferential damping gap suffices for transmitting high damping forces. A suitable magnetic field is applied for damping. Preferably the magnetic field acts on at least 25% of a surface of the annular, circumferential damping gap. The magnetic field influences a surface fraction of the entire peripheral surface of the annular circumferential damping gap that is preferably more than 30% and preferably more than 40% and particularly preferably more than 50%, 60%, 70% or 80% of the peripheral surface of the annular circumferential damping gap. In the sense of the present application a surface portion will count as the surface fraction influenced by the magnetic field if its magnetic field strength is more than 5% larger and preferably more than 10% larger than a magnetic field strength acting on average on the peripheral surface (of the annular, circumferential damping gap).

The rotary damper generates a controlled damper momentum. The damper momentum is preferably directly used for damping a rotary or pivoting motion or for generating a tactile feedback (force characteristic curve; rattling; rippling; virtual stops, force peaks . . . ). The damper momentum may be transformed into a damper force by way of other means serving e.g. for damping the movement of another component. In this respect the rotary damper provides a damper momentum which may be transformed into a damper force acting on another component. The damper momentum and the damper force which may optionally effectively act on another component are interdependent on one another in particular proportionally and in many cases linearly or approximately linearly and—to the extent as it is technically useful—as synonyms in the sense of the present application. At any rate a damper momentum is provided which may be transformed into a corresponding damper force. An effectively acting damper force may also be referred to as a damping force.

The damping gap preferably extends in the axial direction between a first end and a second end and in particular entirely inside the outside component. The damping is preferably performed by way of shearing forces or shear stresses in the magnetorheological medium. The magnetorheological medium remains in the damping gap as a kind of controlled friction lining. The required volume of the magnetorheological medium is minimal and substantially ensues from the volume of the preferably cylindrical damping gap.

In a preferred specific embodiment the two components are pivotable relative to one another only by a limited pivoting angle. The pivoting angle may be limited by way of various measures. A mechanical stop preventing excess pivoting is preferred.

Or else it is possible to provide for kinematic limiting of the pivoting angle wherein the maximum pivoting angle follows from the connected components or devices. For example if the inventive rotary damper is used in a device such as a prosthesis then the components connected with the rotary damper directly limit the feasible pivoting angle. A similar effect occurs with an inventive rotary damper used for example in an accelerator pedal, clutch pedal or brake pedal of a motor vehicle. In these cases the structural conditions of the pivoting angles are again limited naturally or by the mounting space.

Or else it is possible to limit the pivoting angle by the cables or connecting lines to the electric coil. It is possible to have the connecting lines extending one-piece from the outside up to the one or more electric coil(s) for example if a slip ring is dispensed with.

Preferably no slip ring is provided for connecting the electric coils and optionally sensors. Particularly preferably the electric coils and optionally sensors and thus the components for transmitting electric power or signals are connected from the outside through a coil spring such as a long, coiled flat ribbon cable or single-material and in particular one-piece connecting lines without any counterrotating components.

Other configurations having e.g. less strict service life requirements may also provide for a wearing slip ring to ensure contact transmission of the electric connecting lines to the electric coils.

In a preferred specific embodiment the damping gap is formed by a chamber respectively forms part of a chamber. Then the chamber is sealed by the two components and by a sealing device disposed between the two components or else by two sealing devices disposed between the two components. It is also possible to provide three or more sealing devices.

It is particularly preferred for one single sealing device to completely seal the chamber to the outside. This sealing device is provided at a gap between the two components. For example the rotary damper may show a kind of pot or barrel structure with a pivot shaft protruding outwardly from the pot structure. Then the inside component is entirely surrounded by the outside component so that only the pivot shaft of the inside component protrudes outwardly.

Or else it is possible for the axial ends of the damping gap to be provided with a substantially tight magnetic sealing which by way of a magnetic field acting in a narrow gap between the two components interlinks the magnetorheological particles present so as to ensure an at least substantially reliable sealing of the damping gap. A further seal or sealing device may be provided at the housing exit. The housing is preferably formed by the component on which the outside component is configured.

A sealing device in the sense of the present invention prevents in particular unintended mass transfer between spaces. The sealing device may comprise one or more sealing members. Such a sealing device may for example comprise, or be formed by, an O-ring or an X-ring.

In a preferred specific embodiment the chamber is radially disposed between the first component and the second component over its axial length. The chamber is in particular disposed entirely between the first and second components. The chamber may comprise, other than the damping gap, at least one reservoir to store a small and in particular minimal supply of the magnetorheological medium. A maximum reservoir volume is preferably smaller than the damping gap volume and in particular smaller than half the damping gap volume. A reservoir allows to compensate for a certain loss of magnetorheological medium over time without too much increasing the total amount of the magnetorheological damping medium filled in during manufacture.

The reservoir may also be provided with a gas volume in an elastic element configuration to provide slight excess pressure in the magnetorheological medium so as to enable (pressure) compensation e.g. in the case of temperature fluctuations. Moreover the function is ensured, loss of minimal fractions of damping medium notwithstanding. An outside reservoir connected through a line with or without a spring or an air volume or the like is likewise possible.

The radial height of the damping gap is preferably less than 2% of a diameter of the damping gap. A diameter of the damping gap may be understood to mean both the inner diameter and the outer diameter. Preferably the outer diameter of the damping gap is considered as the diameter.

Given an outer diameter of 30 mm the (maximum) radial height will be approximately 0.6 mm. Given an outer diameter of 10 mm the radial height of the damping gap will be 0.2 mm.

Particularly preferably a radial height of the damping gap is less than 1 mm and in particular less than 0.5 mm. In advantageous configurations the radial height is <0.3 mm. Particularly preferably a radial height of the damping gap is more than 0.1 mm and in particular >0.15 mm and it may also be more than or equal to 0.2 mm. If the radial dimensions are provided still smaller this requires observing certain tolerances which would increase the costs for the rotary damper. This is only worthwhile in specific applications.

In advantageous configurations the volume of the damping gap and/or of the chamber is less than 10 ml. Preferably the volume of the damping gap and/or of the chamber is <5 ml and particularly preferably less than 3 ml. Volumes of 2 ml and less are likewise possible and preferred.

In all the configurations it is preferred for the inside component to show the electric coils disposed at the radially extending arms. Or else it is possible for the radially extending arms to protrude radially inwardly from the outside component. It is also preferred for both the inside component and the outside component to show radially extending arms with the radially extending arms then preferably protruding outwardly from the inside component and inwardly from the outside component.

The damper momentum can be varied in particular within less than 20 ms by at least 30% of the required and/or feasible operating range. In all the configurations a control device is preferably assigned to, and/or comprised in, the rotary damper.

The electric coils and optionally sensors are connected through electric connecting lines which are in particular routed outwardly inside or outside the inside component. For example the connecting lines may be routed outwardly through the inside component and through the pivot shaft therein, one-piece or single-material, without a slip ring. Or else it is possible for the connecting lines to be routed through and outwardly outside of the pivot shaft. Particularly preferably the electric coils and optionally sensors and thus the components for transmitting electric power or signals are connected from the outside through a coil spring such as a long, coiled flat ribbon cable or single-material and in particular one-piece connecting lines without any counter rotating components.

Other configurations having e.g. less strict service life requirements may also provide for installing a wearing slip ring or the like.

Preferably the magnetic field generating devices show opposite poles at the adjacent ends of adjacent arms of at least one component. Particularly preferably an even number of arms is used. Preferably at least 4 arms are provided. Preferably, 6, 8, 10, 12, 14 or 16 arms are employed. The number of arms may depend on the size of the rotary damper and may be higher still.

The outside component is preferably part of a housing accommodating the inside component. A pivot shaft of the inside component is preferably routed outwardly from the outside component.

It is preferred for one of the pivot shaft ends to be routed out of the housing and for the other of the pivot shaft ends to terminate within the housing. This configuration requires to provide one seal or sealing device only for sealing the housing to the outside. The pivot shaft may be supported within the housing on one or two bearings or the like so as to enable low-friction rotation. The bearing may be a low-cost sliding bearing or else, in the case of very high requirements on the base friction and service life, it may be a ball bearing or roller bearing. In the case of minimal requirements it may be dispensed with.

It is also possible for the pivot shaft to be routed outwardly through the housing on both sides so as to guide the first end of the pivot shaft out of the housing on one side and on the other side the other end of the pivot shaft protrudes outwardly from the housing. This configuration allows a symmetric accommodation of the rotary damper which may prove advantageous for the rotational force transfer.

In all the specific embodiments it is possible to also mount on the pivot shaft a toothed wheel which is then in functional connection or meshing with a toothed rack or other gear wheels.

In all the configurations at least one suspension device is preferably provided for building up a counterforce as the two components deflect in at least one pivoting direction.

Such a suspension device is advantageous since it allows to bias the rotary damper to a base position. The suspension device may be provided both at the rotary damper or within the housing of the rotary damper. Or else it is possible for the suspension device to act on the outside of the rotary damper or to be provided as a separate component which is an element of a device employing the rotary damper. This includes but is not limited to linear springs, leg springs, coil springs, flat springs, torsion springs, helical tension springs or compression springs.

In all the configurations it is possible to provide a multitude of damping gaps distributed over the circumference of the component. Separating elements may for example be provided in the annular space in which the one or more damping gap(s) is/are configured. These separating elements may for example protrude outwardly from the inside component or protrude inwardly from the outside component. These separating elements extending in the axial direction or helically subdivide the annular space into multiple damping gaps. Since the separating elements then transmit a force, the separating elements ought to be fixedly connected either with the inside component or the outside component.

In advantageous configurations a permanent magnet is assigned to at least one electric coil. This means that the magnetic field generating devices comprise, other than an electric coil, also at least one permanent magnet. The magnetic field of the permanent magnet may be influenced by way of the assigned electric coil. The magnetic field of the permanent magnet may in particular be continuously varied and/or permanently changed by way of short pulses of the electric coil. Continuously varying the magnetic field of the permanent magnet allows a temporally continuous and infinite adjusting of the acting magnetic field. For example the effectively acting magnetic field may be reduced to nearly 0 or else to 0, or the magnetic field polarity may be reversed.

These measures allow to set a specific magnetic field and thus a specific basic damping which acts permanently, independently of any power supply. In preferred specific embodiments the length of the damping gap is larger than its diameter.

In all the configurations it is possible and preferred for the magnetorheological medium to contain a suspension of ferromagnetic particles in a medium such as oil, glycol or grease and/or wherein the medium contains stabilizers.

Preferred specific embodiments of the rotary damper according to the invention may be provided for a car door, a brake pedal, clutch pedal, or accelerator pedal. Use in a prosthesis, an exoskeleton, a piece of furniture, fitness apparatus, or a bicycle is also possible. Operation may be carried out by way of an operating or control lever.

Therefore we also claim an apparatus configured as a training apparatus or fitness apparatus having at least one rotary damper according to the invention. In the scope of the present invention a training apparatus is in particular also understood to mean a fitness apparatus and vice versa. The training apparatus is suitable and configured for controlled muscular activities. It comprises at least one at least partially muscular energy-actuated operating member. At least one operating member movement can be damped by the rotary damper.

In a feasible variant a customer enters e.g. a fitness center and goes to a body scanner and/or an analyzer. The analyzer determines and stores the “leverage ratios” (e.g. upper arm, forearm, thighs, body height . . . ). The customer receives a device (e.g. NFC bracelet, chip, a smart device such as a smartphone or smart watch or the like) which transmits this data to the fitness apparatus during use. Thus it will always show optimal settings for training (e.g. force over travel; momentum over angle, or the like) or advises the user on adjustments (e.g. adjust the seat mechanically or the like) or the device self-adjusts (e.g. by means of electric motors or the like).

In another conceivable variant the customer carries the data on his person (e.g. by way of a smart watch, smartphone, chip or the like). He can thus immediately start in any fitness center (worldwide) which can process this data or has suitable fitness apparatus (user retention).

Both of these or other variants transmit the data further from the fitness apparatus to a “memory”, analyzing it (e.g. cloud, internal memory or the like). The customer can then process the data e.g. at home.

The data preferably causes refining of the user profile (e.g. a learning configuration may be provided). The data may also be compared against those of colleagues and optimized (e.g. by way of a community, cloud or the like).

Preferably a log file is created displaying the course and success of the training. Or else the data may be transmitted to a diagnostic center, doctor, coach or health insurance agency, for them to verify what had been done and how.

Preferably at least one control device is provided and suitable and configured for controlled adjustment taking into account at least one predetermined parameter of the damper. Adjusting is preferably performed in real time. For example the force desired for a muscle exercise may be provided as a parameter. The damper is then adjusted so that the user must apply the force for moving the operating member.

Preferably the control device is suitable and configured to register at least one characteristic quantity of the movement of the operating member. The control device is in particular suitable and configured for controlled setting of the damping of the rotary damper, taking into account the parameter in dependence on the characteristic quantity.

The characteristic quantity of the operating member movement is in particular captured by at least one sensor. Capturing takes place in particular continuously. For example by means of one of the sensors presently described and preferably by the rotary encoder. Then the parameter preferably relates to a threshold value and/or a comparison operation for the characteristic quantity. Or else, a predetermined parameter and captured characteristic quantity may be assigned by way of an electronic map.

The coach may for example specify a parameter such as a value for the force/rotational force desired in an exercise. Then the force/rotational force applied by the user is captured as the characteristic quantity of movement of the operating member and compared against the specified value. When the user exceeds the value, the damper settings may be adjusted weaker or movable more easily. This effectively prevents overstressing the muscle in training. This is an advantage in particular in rehabilitation measures where overstressing must needs be avoided. Alternatively the damper may output a tactile feedback to the user. As overstressing is registered the damper may be switched to zero or a very low force.

Preferably the characteristic quantity describes an angular position and/or a direction of movement and/or a rotational force of movement and/or acceleration of the operating member. These characteristic quantities are particularly advantageous since they are characteristic of the user's muscular activities at the training apparatus.

The damper is particularly preferably adjusted as a function of the characteristic quantity. The damper is in particular adjusted dynamically and/or adaptively. This shows the advantage of allowing a much higher degree of customized training than has been possible with weight pulls or conventional linear damper settings. Thus, training movement may start using slight force and may increase in weight with increasing stroke length and/or angle of rotation. The force applied may be set in real time in dependence on an acceleration registered as a characteristic quantity. Differentiating between the left and right sides of the body and adapting correspondingly is also possible.

Or else the training program can be varied a number of times and individually during the training period.

The characteristic quantity may for example describe the angle of rotation in straightening the knees. Then the damper and thus the required muscular energy may be set in dependence on the angle of rotation. The force for example decreases as the knee straightens progressively. This prevents harmful training stresses. The damper may be set to zero force for a critical angle of rotation so as to prevent harmful overstretching.

Critical angles or positions may be predetermined based on injuries or due to physiological conditions. The damper can be preset precisely to these conditions (personalized training).

Since some people tend to perform exercises too hasty and too fast, which puts increased or even harmful stress on joints and muscles, the damper may be adjusted or it self-adjusts automatically in these situations so as to disable or prohibit fast displacement/movement. Then the damper settings may be very soft or it may output a tactile feedback.

Or else it is possible for the characteristic quantity to describe the direction of movement. This allows to set different forces e.g. for straightening the knees and for the return movement, bending the knees. For many muscle exercises it tends to be highly decisive that the return movement be performed using a force lower or else larger than the forward movement.

During training a tactile feedback may be output to the user. This is in particular done by controlled changes to the damping characteristics and preferably as described above. The feedback is in particular output in dependence on the characteristic quantity of the movement. For example the damper may be set to issue a tactile rattling or juddering if the characteristic quantity shows that the user performs an exercise too fast or too forceful. The feedback may also be output if the user exceeds an angle of rotation or a distance of movement or if he performs a flawed movement sequence. Thus the user may learn the correct performance of the exercises in an easy and simple way.

It is also possible to output the feedback taking into account other sensor values serving as a characteristic quantity. The control device may for example register pulse values, heart frequency, and other vital parameters on which to base the damper settings. If the user overexerts himself (state of exhaustion) or if he lies outside a useful training range, the tactile feedback points this out and/or the damper adapts automatically and adaptably so as to cause the user to revert to a useful training range which is preferably not detrimental to his health.

The damper properties may also be adjusted taking into account other sensor values and for example the vital parameters for the characteristic quantity. Thus the required force may be increased as the user's pulse indicates a warmed up muscular system. It is also possible, until a specific vital parameter value or other characteristic quantity is registered, for the damper to be set hard enough for specific angles of rotation so that the user cannot bring the operating member to this angle of rotation. This prevents straining the muscles as training begins.

In preferred specific embodiments the rotary damper according to the invention may be employed in fitness apparatus as a damper and in particular a hybrid damper for existing systems. In this case the rotary damper which e.g. shifts in the range of milliseconds and continuously may be connected in parallel to an existing, comparatively inertial brake (e.g. friction brake, eddy-current brake or other suitable brake) in a training apparatus and e.g. a fitness bicycle (e.g. cycle exerciser or the like). This allows to compensate peak loads (e.g. due to kinematic conditions), non-uniformities, vibrations, wear and tear, bearing play and other play etc. This is advantageously done as a controlled system.

Hereinafter, “single action” e.g. refers to one pedal turn in a stationary bicycle, a partial or complete rowing movement (e.g. drive, stroke, recovery or the like) in a rowing machine, opening and closing a door etc. Or else it may mean a movement of the operating member of the training apparatus.

The inventive rotary damper may be employed as one single energy conversion member (e.g. a brake or the like) so as to enable hitherto impossible or highly individual force/rotational force flows. It is thus possible to vary e.g. the operating force/momentum not only from one single action to the next single action (e.g. not only per full rotation, per full stroke) but even during one single action. In particular can the force/momentum be varied by way of travel/angle so as to result in a repeatedly changing momentum during one rotation and thus in a controlled torque characteristic/characteristic curve during one rotation).

In the case of a rowing machine one can thus generate e.g. during a complete rowing movement sequence the precise characteristic torque curve (e.g. force curve of the human hand), adequately to a rowing movement in a boat in the water. The inventive rotary damper preferably simulates the rowing or actuating kinematics, depth of plunge, displacement speed, pitch angle of the blade, and many more force curves of this sport.

In all the configurations it is possible to realize an e.g. adaptive door damper. To this end e.g. a parking space for a vehicle may be measured for parking. The data obtained allows to calculate the distance from the adjacent vehicle. On this basis the maximum door angle available for opening may in turn be calculated and as or even before it is reached the opening process can be damped and/or limited.

The one or more sensor(s) for measuring the distance of the vehicle during parking may be used so as to dispense with separate sensors. Or else it is possible to provide controlling so as to first open the door slightly and then to apply a grid of increasing fineness. This virtually realizes a tactile indicator for door openers, warning of an approaching stop.

It is also possible to keep doors, windows or the like open at specific angles. This may be realized e.g. in motor vehicles or else with furniture.

The rotary damper may be used as a tactile knob providing a sensible grid in rotating so as to result in a tactile feedback in a rotating or pivoting motion of the tactile knob. Such a grid may be generated by a control device in which the electric coil is periodically energized at specific time intervals or the like so as to periodically change the swiveling resistance. The tactile feedback or the damping strength may be changed adaptively so as to obtain a wide variety of applications. Therefore, an apparatus is also claimed comprising at least one rotary damper that is configured as described above.

The rotary damper may also be used as a vibration damper in or at a pivot point of the swing arm rear suspension or as a steering damper of motorcycles and bicycles, although it is not limited thereto. This can considerably reduce or nearly entirely or completely avoid handlebar wobbling, which may be dangerous, in the case of an unweighted or lifted front wheel. Undesirable vibrations in the steering such as high speed wobbling can (moreover) be reduced. The rotary damper, which may also be referred to as a shear damper, may be installed directly in the steering head (steering head lug in which the fork column pivots).

The inventive rotary damper provides an advantageous device for damping vibrations wherein for damping translational movements, such translational movement can first be converted into a rotational motion so as to then damp the pivoting motion. The damping strength can be changed at high speed so as to change damping from a minimum to a maximum value within a few milliseconds.

The rheological fluid may consist of a great variety of components provided singly or in combination: Fe, high-carbon steel, NdFeB (neodymium), alnico, samarium, cobalt, silicon, carbon fiber, stainless steel, polymers, soda-lime glass, soda-lime-silica glass, ceramics, and non-magnetic metals and the like. Dimorphic magnetorheological fluids with carbon nanotubes or/and nanowires are also possible.

The carrier liquid may in particular consist of the following components or a combination thereof: oils and preferably synthetic or non-synthetic oils, hydraulic oil, glycol, water, fats and the like.

For the damper to follow the desired specifics as rapidly as possible, a construction is advantageous where the magnetic field acting in the damping gap can change very rapidly. Particularly suitable in the magnetic circuit is a material that is readily magnetizable (high permeability) and does not retain any or hardly any remanent magnetization (low coercive field strength). Moreover it is intended to damp the eddy currents induced by variations of magnetic flux by way of poor electric conductivity. Eddy currents can be particularly effectively damped by a laminated magnetic circuit structure of ferromagnetic sheet metal.

The magnetic circuit and the electric coil are preferably configured so as to provide the coil with the lowest inductance possible. It is advantageous to supply the coil with an operating voltage higher than required for driving the maximum current (voltage boost) so as to enable considerably faster sudden current variations. Pulsed driving furthermore allows to set any desired current. A full-bridge (H-bridge) driving is for example suitable for rapid current intensity changes in both directions, i.e. power amplification and attenuation.

The energy required for rapid load alterations is preferably provided by a low-impedance source such as a capacitor or a battery in the vicinity of the consumer.

In the most ordinary configuration a switch may be a mechanical switch/push button; the use of a transistor is advantageous. Other possibilities are conceivable as well such as a relay or else special transistor types (MOSFET, IGBT). The switch may among other things also be provided in the GND branch, i.e. between the coil and ground (GND). The current may be measured in any desired spot in the circuit. A flyback diode allowing the electric coil to continue to drive current after opening the switch may likewise be provided. The diode may also be replaced by a switch (Sync-FET).

Driving by way of a full bridge (H bridge) is also possible. The electric coil can thus be controlled in both directions, i.e. the polarities at the electric coil connections can be switched. This allows to boost or attenuate e.g. a permanent magnet in the magnetic coil circuit. In the case of pulsed driving (PWM) the coil current may be varied. Other than the simple controlling option, this configuration also allows to equip the controller with various sensors enabling to build up a control circuit. Depending on the intended purpose, e.g. pressure, force, travel, temperature, speed, or acceleration sensors may be used. A combination of these or other sensors is also conceivable.

A control unit (electronics) processes the system quantities and kinematic quantities preferably continuously, and on the basis of the measurement data and the known system behavior, determines the suitable damper force or the suitable damper momentum.

A controller and/or control unit may be based on fuzzy logic and/or learning.

Controlling may be provided as learning/self-learning for influences such as aging and/or temperature factors. Furthermore it may be learning/self-learning for optimal damping for specific movement profiles. Specific or recurrent load conditions may be taken into account.

The controller may be provided for autonomous learning or for user optimizing/adapting.

To allow recognition of suitable/optimal damping for any and all conceivable operating states, characteristic quantities are generated on the basis of all the measured quantities available in the system. They signal whether damping is set adequately or less than optimal. These characteristic quantities are preferably generated continuously/periodically at fixed time intervals.

The characteristic quantities represent a degree of the damping quality. Computation may be based on any and all measured quantities available in the system. Preferably the kinematic quantity information of all of the actuators available in the system is used.

The characteristic quantities are preferably computed by way of directly processing the sensor signals and/or through algorithms further processing this information; for example frequency analyses etc.

The characteristic quantities represent for example a measure for vibrations and/or ripples. Alternative expressions of characteristic quantities are likewise conceivable.

Then the controller can interpret these characteristic quantities.

Generally speaking, any and all available system information, specifically the kinematic actuator quantities, can be used for the purpose of monitoring.

Monitoring preferably takes place in real time. Or at best at fixed time intervals. Time intervals<10 ms appear to be realistic and advantageous.

The user of the device may likewise interpret these characteristic quantities. Output is for example provided on a display etc.

It is possible for the user to manually adjust the damping characteristics in operation to generate optimal damping for any operating state. The interpretation of the damping quality then in particular takes place through the automatically generated characteristic quantities.

The user thus has the option to personalize actuating sequences. This allows to obtain and store optimal damping characteristics for specific loads in specific operating states. Obtaining/storing time sequences of the damping characteristics is also conceivable.

Thus the user may generate/store/retrieve specific optimal actuating programs for specific/recurrent actuating patterns.

It is thus for example possible to generate energy-efficient or userfriendly actuations for retrieval for recurrent applications.

It is likewise possible to provide a control unit for automatic learning/carrying out all of the above.

It is for example conceivable to have the control unit advise the user about the characteristic quantity following each operation on the basis of the obtained characteristic quantities for optimal damping.

Then the user can store the time sequence for future recurrent operations.

The controller may furthermore be provided for self-leaning and/or automatic response to aging phenomena, correspondingly adapting the controlling of the actuators to ensure always optimal damping.

The controller may furthermore be provided for self-leaning and/or automatic response to temperature influences, correspondingly adapting the controlling of the actuators to ensure always optimal damping.

The temperature in the actuators may markedly increase in operation so that the damping characteristics may noticeably vary in auto-controlling. It is therefore advantageous to compensate the temperature influences by an always consistent behavior in the course of controlling.

Conventional actuators do not provide for this.

The present system can achieve this by way of measuring the actuator temperature—for example with a PT1000 in the coil or alternative concepts—and adjustment corresponding to the known temperature influences is performed on the basis of the temperature information.

The kinematic actuator quantities may be measured directly e.g. by displacement sensors, speed sensors, or acceleration sensors.

It is furthermore conceivable to generate the pertaining kinematic quantities by way of suitable algorithms on the basis of a measured quantity. The base measured quantity employed may include e.g. displacement sensors, speed sensors, or acceleration sensors. The algorithms are preferably based on a Kalman filter. Alternative signal processing algorithms are likewise conceivable.

At least one suitable control algorithm is preferably used for computing the optimal damping force for at least part and preferably all of the actuators (dampers) used at any random controlling time. Clock cycles of up to 50 microseconds may be required for optimal control. To this end in particular a plurality and preferably all of the information is taken into account relating to the currently prevailing kinematic quantities of a plurality and preferably all of the employed actuators. Furthermore, in particular a plurality and preferably all of the information from a plurality and preferably all of the available system quantities is taken into account such as all of the measured system accelerations.

A primary central control unit may be provided for computing the optimal damping for each of the actuators (dampers) employed. The information on optimal damping is then transmitted to the pertaining actuators for implementing/generating.

It is likewise possible to provide for a decentralized computation of the optimal damping for each of the actuators (dampers) employed. Each of the actuators possesses its own control unit to compute and implement the pertaining information.

It is likewise possible for each of the actuators to possess its own control unit, one of the control units operating as a computing center. It represents the master electronics and processes/computes the primary controlling strategy, transmitting the pertaining information on optimal damping to the other actuators available in the system (slaves).

Other than computing the optimal damping in particular for any and all of the actuators available in the system it is important to ensure by means of suitable control for the actuator to implement this optimal damping on schedule. The operative actuator momentum is proportionate to the coil current. The optimal damping information is accordingly proportionate to the coil current. Accordingly a control unit must ensure that the real coil current in operation corresponds to the computed coil current for optimal damping. Due to the prevailing coil inductances no sudden current variations in the coil and thus no sudden actuator momentum variation can be generated. Preferably at least one current regulator is used to minimize the ensuing time constants. The current regulator is in charge of causing the real coil current to follow the intended coil current as quickly as possible (for optimal damping).

A central control unit may take over the implementation/computation/realization of the current regulator for all the actuators used in the system.

It is likewise possible to provide for a decentralized implementation/computation/realization of the current regulator for one single actuator (damper) employed. Each of the actuators possesses its own control unit to compute and implement the pertaining information.

Any form in particular requires the information on the prevailing coil current for a current regulator. Suitable sensors—e.g. shunt etc.—may be used for obtaining the information. A frame of reference for estimating the prevailing coil current is likewise conceivable.

The current regulator may be considered to be a momentum control.

At least one torque sensor may be employed for more precision of momentum control. Then the moment of resistance of the one or more actuator(s) is controlled by way of the sensor signal of the torque sensor and a current regulator may be dispensed with.

A combination of a current regulator and a primary torque regulator is also conceivable.

The primary computation of the optimal damping may in turn take place centralized or decentralized.

These two controlling tasks may be considered separately from one another.

An algorithm may take into account and compensate for any aging phenomena in the system which may change the operating performance.

Depending on the material used, a permanent residual magnetic field may remain in the material, depending e.g. on the number of switching actions (on/off). This will raise the base momentum. An alternating field showing decreasing amplitude may eliminate the residual magnetic field as needed or on a regular basis.

This allows to accept larger material tolerances etc. regarding the quality which in turn reduces manufacturing Costs.

The range between the minimum and required maximum force or minimum and required maximum momentum is the required operating range.

An apparatus is preferably equipped with at least one rotary damper providing for the rotary damper to damp linear movement.

Further advantages and features of the present invention can be taken from the description of the exemplary embodiments which will be discussed below with reference to the enclosed figures.

The figures show in:

FIG. 1 a schematic, exploded view of a rotary damper according to the invention;

FIG. 2 a schematic cross-section of the rotary damper of FIG. 1;

FIG. 3 a perspective view of part of the rotary damper of FIG. 1;

FIG. 4 a schematic cross-section of the rotary damper of FIG. 1;

FIG. 5 schematically illustrated magnetic field lines in the rotary damper of FIG. 4;

FIG. 6 a cross-section of another rotary damper;

FIG. 7 a schematic perspective view of an operating pedal;

FIG. 8 a schematic view of a prosthesis; and

FIG. 9 a simplistic sketch of the damper device control;

FIG. 10 a simplistic sketch of another configuration of the control of the damper device; and

FIG. 11 a training apparatus or fitness apparatus.

FIG. 1 shows a schematic perspective view of a damper device 10 comprising a rotary damper 1, wherein the individual parts of the rotary damper 1 are recognizable.

The rotary damper 1 is substantially formed of the components 2 and 3 with the pivot shaft 4 disposed or configured on the component 2. The pivot shaft 4 comprises a first end 31 and a second end 32. The component 2 shows over its circumference a number of arms 21, 22 and 23 which will be discussed in more detail in the description of the FIGS. 3 to 5.

The pivot shaft 4 may be provided with an engaging dog 4 a (e.g. parallel key) for non-rotatable connection of the component 2 with a damped component. A splined toothing, polygon connection or another force-fit or form-fit connection may be used instead of the parallel key. For mounting the component 3 is pushed onto the component 2 and then screwed to the cover 3 a, the first end 31 of the pivot shaft 4 extending outwardly from what is shown as the right end of the component 3. Spacer sleeves 38 may be used to observe predetermined distances.

Basically, two variations are possible namely, the second end 32 of the pivot shaft extends outwardly on the other side of the component 3, or else the second end 32 of the pivot shaft 4 is supported in the interior of the component 3, e.g. in the bearing 37 of the cover 3 a consisting e.g. of aluminium or the like. The bearing 37 may be a low-cost sliding bearing or else, in the case of high or very high requirements on the base friction and service life, it may be a ball bearing or roller bearing. In the case of minimal requirements it may be dispensed with.

A rotary encoder or angle sensor 17 serves to capture the relative angular position of the components 2 and 3 relative to one another. The angle sensor 17 may comprise a magnet stack and may be provided for contactless reading from outside the housing 30. The sensors may be disposed on coupling members or operatively coupled parts. A linear measuring system instead of a rotative measuring system may be used.

The connecting lines 14 supply electric energy to the rotary damper 1.

Furthermore shown are from left to right, a collar end bearing, a shim ring, another collar end bearing, seals and bearings, spacer sleeve etc.

The components 2 and 3 may be conical in shape. The damping gap 6 does not need to be consistent in size or shape over the axial extension 16.

FIG. 2 shows a schematic cross-section in the assembled state, revealing that in the assembled state the component 3 forms a housing 30 of the rotary damper 1. The component 3 receives in its interior the substantial part of the component 2 so that after screwing the cover 3 a onto the component 3 only the first end 31 of the pivot shaft 4 protrudes outwardly out of the housing 30. The engaging dog 4 a is disposed on the part protruding outwardly of the pivot shaft 4. The component 3 comprises an outside component 13 and forms the housing 30. The component 2 comprises an inside component 12 that is surrounded by the outside component 13.

The pivot shaft 4 is supported by way of a bearing 37 in the vicinity of the first end 31 and the other end 32 is provided with a presently spherical mounting having a kind of bearing 37 so that the pivot shaft 4 only passes through outwardly. This allows to reduce the base friction and thus the base momentum so as to achieve higher sensitivity and better responsivity of the rotary damper 1 to loads.

A geometric axis 9 extends centrally through the pivot shaft 4. The electric connecting lines 14 also extend through the pivot shaft 4, passing from the outside (absent a slip ring) through the pivot shaft 4 to the electric coils 8 disposed in the interior of the housing 30.

In this simplistic cross-section of the rotary damper 1, two arms 21, 22 can be seen on the inside component 12 of the component 2.

The damping gap 6 is provided radially between the inside component 12 and the outside component 13 and extends over an axial length 16 which comprises a substantial part of the length of the inside component 12. The length 16 of the damping gap 6 is preferably at least half and in particular at least ⅔ of the length of the component 3.

Given large diameters 27 of the damping gap 6 it is in particular possible to provide each of the axial ends of the damping gap 6 with seals to contain the magnetorheological medium substantially, and preferably entirely, within the damping gap 6. Simple configurations may provide for a magnetic seal for magnetically sealing the very narrow gap still remaining between the components 2 and 3.

At least one seal is provided at the exit of the very thin pivot shaft 4 out of the housing 30. In this case the seal 11 is provided between the pivot shaft and the corresponding lead-through opening in the cover 3 a.

Absent a separate seal at the axial ends of the damping gap 6 there is a very low base friction. The volume of the magnetorheological medium is determined by the volume of the damping gap 6 and the approximately disk-shaped volumes at the two axial front faces between the inside component 12 and the outside component 13 and it is small on the whole.

The volume of the damping gap 6 is very small since the radial height of the damping gap is preferably less than 2% of the diameter 27 of the presently cylindrical damping gap. The radial height of the damping gap is in particular less than 1 mm and preferably less than 0.6 mm and particularly preferably less than 0.3 mm. Given a length 16 of for example up to 40 or 50 mm and a diameter 27 of up to 30 mm and a gap height in the region of 0.3 mm, there ensues a gap volume of <2 ml, which allows to keep the manufacturing costs down. The volume of the magnetorheological medium is in particular less than 3 ml and preferably less than 2 ml.

A prior art transmission may be positioned between the pivot shaft 4 and the damped member, preferably a planetary gear largely without play, a micro transmission or e.g. a harmonic drive.

A disk may be positioned on the input shaft instead of a direct seat mounting or seat mounting via a coupling linkage. The disk or the outer disk diameter may be connected with the damped member (force-fit or effective fit) by means of at least one rope or belt. The connecting member may be connected for interaction with the damped member by means of deflections, gear ratio translation (e.g. block and tackle principle . . . ). This provides high structural flexibility in terms of attaching. Or else an eccentric or cam disk may be used so as to make the forces/momenta dependent on the angular position. Or else a continuous rope with a fixing spot may be used so as to enable positive control, i.e. both tractive and compressive forces can be transmitted. The transmission member (e.g. the rope) may be connected with the disk by way of force-fit or form-fit.

FIG. 3 shows a schematic perspective illustration of a part of the rotary damper 1 wherein the component 2 is illustrated absent the pivot shaft 4. In mounting, the illustrated part of the component 2 is non-rotatably coupled with the pivot shaft 4.

The component 2 comprises a plurality of radially outwardly protruding arms 21, 22, 23 etc. In this instance, eight arms are provided. Or else, 6 or 10 or 12 or more arms are possible and preferred.

A coil 8 having at least one and presently a plurality of windings is wound around each of the arms. The electric coils are wound and connected such that adjacent spots of adjacent arms show opposite magnetic field poles when the coils 8 are energized.

FIG. 4 shows a cross-section of the rotary damper 1, the component 2 comprising the inside component 12 that is surrounded by the outside component 13 of the component 3. In this instance a substantially cylindrical damping gap 6 containing a magnetorheological medium 5 extends between the two components 2 and 3. The damping gap 6 is in particular entirely filled with the magnetorheological medium 5. At least one reservoir 15 may be provided in which a supply of magnetorheological medium is stored to enable compensating losses of certain amounts of the medium throughout the service life of the rotary damper 1. This reservoir 15 may for example be provided in the clearance between two arms 22, 23. Or else the reservoir may be located external of the component 3.

In manufacturing, the coils 8 are first wound around each of the arms. Thereafter the remaining hollow spaces between the arms may be partially or entirely filled with a medium so that no magnetorheological fluid needs to be filled in. For example casting resin or the like may be poured in for filling up the hollow spaces. Casting resin or the like is lower in cost than the magnetorheological fluid. The function does not require filling up the hollow spaces. Or else it is possible to apply a thin protective layer in the shape of a covering 34 to delimit the locations of the damping gaps 6 while the clearances between arms remain hollow.

The damping gap is preferably cylindrical. Or else it is possible to dispose separating elements 29 in the coupling gap which subdivide the per se cylindrical coupling gap into a number of partial gaps. The separating elements 29 are preferably connected either with the component 2 or the component 3.

The coupling gap 6 itself may form the chamber 28 for the magnetorheological medium or else the coupling gap 6 together with the reservoir 15 forms at least a substantial part of the chamber 28.

FIG. 5 shows a simplistic view of a field line pattern over the cross-section of the rotary damper 1 in FIG. 6. The field lines 36 pass approximately radially through the damping gap 6, run across an angular section through the component 3 before re-entering (the adjacent arm) next to the adjacent arm approximately vertically through the damping gap 6.

FIG. 5 illustratively shows that a high field line density prevails virtually over the entire circumference of the rotary damper so as to enable effectively damping a pivoting motion.

FIG. 6 shows another configuration of a rotary damper 1 whose functionality is basically identical to that of the rotary damper 1 described above. Unlike the previous configurations the rotary damper 1 according to FIG. 6 provides for the pivot shaft 4 to protrude outwardly both at the first end 31 and also at a second end 32. This is why the pivot shaft 4 is supported at both ends and sealed outwardly by means of seals 11. Again, magnetic seals 11 a may seal the damping gap 6 in the axial directions.

In this and also in the other configurations the pivot shaft 6 may be standing upright, i.e. as an axle, wherein the housing 3 then pivots while damping and is operatively coupled with the damped member.

FIG. 7 shows an operating pedal 100, such as a brake pedal, a clutch pedal or an accelerator pedal with an integrated rotary damper 1.

So-called “X-by-wire” systems show increasing use in many fields of application. X-by-Wire designates the replacement of mechanical connections, signals and systems for manual control by guiding electric, electronic, optoelectronic or optical control signals between the operating members used and the executing actuators. A major drawback of these systems is the absence of feedback, which is a serious disadvantage e.g. when operating the X-by-wire foot brake of a vehicle (e.g. motor vehicle, truck, agricultural vehicle, utility vehicle, crane, building vehicle). For example “braking by feel” is thus no longer possible. Overbraking may result in instable driving situations, overloads, or uncomfortable braking manoeuvres. The rotary damper 1 presently described can simulate the braking counterpressure or the corresponding momentum which is otherwise generated mechanically, thus simulating a “normal” braking or operational feel in the pedal.

This is particularly advantageous in hybrid vehicles. Hybrid vehicles may be provided with pedals and operating members connected by “X-by-wire” or else mechanically. In these vehicles the brake energy recuperation causes changing actuating forces and/or actuating momenta respectively actuator travels. For example when a hybrid vehicle travels downhill, reducing the speed preferably involves the attempt to transmit the smallest amount of energy possible to the wheel brakes (heat) and the largest amount possible to the batteries (electric energy is fed into the accumulator, a storage capacitor (super capacitor), or a flywheel storage).

It may thus happen that the batteries are empty as the ride downhill begins and the vehicle can virtually be “braked” by brake energy recuperation only. This only requires a very slight pressure applied on the brake pedal, and the rider receives a very low counterforce although the vehicle markedly retards by way of the brake energy recuperation, e.g. of the electric motor (generator) actuated in parallel. The more energy is stored in the electric energy storage device, the less braking is possible involving brake energy recuperation. This results in the fact that the “braking point” and the “braking force” in the pedal vary continuously which is very unpleasant and confusing or even downright dangerous for the operator. The rotary damper according to the invention can generate the differential torque/force corresponding to the energy distribution and can thus simulate in the pedal a “normal” feel that always remains constant.

In the case of an operating lever such as an accelerator pedal the subsequent conditions can at least partially be taken into account and converted into an individual tactile feedback by means of the rotary damper according to the invention.

For example when a vehicle in front is recognized, a higher counterforce in the operating lever may be set in the case of a too close distance or if the vehicle in front decelerates). Or else an in particular early danger warning relating to the vehicle in front is possible. For example accelerating may then be prohibited. This is in particular realized by an increased counterforce up to a locked pedal.

The accelerator pedal is for example connected with the overall vehicle system and e.g. a cloud (in particular relating to the navigation system, engine management system, optimal shifting time, start-stop system, electric driving in hybrid vehicles, adaptive operation, or the like). A counterforce/momentum depending thereon in the operating member is preferably set.

Or else, near field and/or surroundings sensors may be provided and referred to. Then an adaptive counterforce is in particular set.

This applies accordingly to the brake pedal or other operating members.

Furthermore the rotary damper enables a feedback and damped resetting and/or actuating of the pedal which enables advantageous operation. A combination with a return spring is likewise possible.

The actuating travel and thus the pivoting angle is limited by the mounting space.

In the case of the operating pedal 100, the operating pedal may (also) damp vibrations originating from the outside such as with use on vibrating construction machinery etc. These or other acting vibrations might cause a certain actuation of the operating pedal. The rotary damper respectively the assigned or integrated control device can differentiate whether these vibrations originate from the vehicle or from actuating movements by the operator.

FIG. 8 shows a prosthesis with a damper device 10 comprising a rotary damper 1. The components 2 and 3 are connected with prosthesis parts and damp the relative motions.

On the whole the damper device 10 of FIG. 8 supplies a knee joint suitable for effective damping.

The FIGS. 9 and 10 show simplistic embodiments of a controlling system of the damper device 10.

In the scope of the present invention the term controlling is understood to include regulation so that the controlling system is preferably also suitable and configured for regulation.

In this instance only three switched rotary dampers 1 acting as actuators are shown. However, four or five or else 10 or a plurality of controlled actuators may be provided. Or else it is possible to provide only one actuator or two actuators.

The shown dampers 1 are operatively coupled with a computer 201. The computer 201 receives for each damper 1 at least one actuator signal 204 describing at least one characteristic quantity for at least one state of the damper 1. An actuator signal for example comprises a characteristic quantity captured by the rotary encoder 17. The actuator signal may also comprise a characteristic quantity captured by at least one momentum sensor and/or at least one current sensor. Other suitable sensor types are likewise possible. Particularly preferably the computer 201 takes into account a plurality of actuator signals 204 originating from different sensors.

The computer 201 preferably also takes into account at least one piece of system information 203 that describes at least one system quantity. The system information 203 comprises for example acceleration values of the drum 101 and/or of the drum housing 109 and/or further system quantities.

By way of the provided actuator signals 204 the computer 201 determines for the dampers 1 at least one characteristic quantity each for an optimal moment of resistance. The characteristic quantities for the determined moments of resistance of the dampers of an actuator are each provided for a current/torque regulation 202 assigned to a damper 1.

The current/torque regulation 202 outputs for each damper 1 at least one control voltage 205 in dependence on the provided moments of resistance. Or else, actuating signals are possible showing quantities suitable for controlling the damper 1 other than and/or additionally to the voltage. The pertaining damper 1 is adjusted by way of the control voltage 205.

The control shown in the FIG. 9 is configured as a central control 200. The central control 200 comprises the computer 201 and the current/torque regulation 202 assigned to the pertaining dampers 1.

A configuration not shown may provide for a decentralized configuration of the current/torque regulation 202 assigned to the pertaining dampers 1. The computer 201 maintains its central status. To this end the current/torque regulation 202 is disposed in particular separately and spatially separate from the computer 201.

FIG. 10 shows a control configured as a decentralized control 206. At least one dedicated computer 201 and at least one dedicated current/torque regulation 202 is assigned to each of the dampers 1. It is possible for the computer 201 and the current/torque regulation 202 assigned to a damper 1 to be configured for autonomous action. Or else a configuration is possible in which the decentralized control 206 also takes into account system information 203.

FIG. 11 shows an apparatus configured as a training apparatus 300 or fitness apparatus comprising a damper device 10 according to the invention. The training apparatus 300 is configured as a stationary bicycle. It comprises a muscular energy-actuated operating member 301 which is configured as a pedal crank device having one pedal and one bottom bracket or pedal bearing. The rotary damper 1 can damp the movement of the operating member 301.

The damping characteristics of the rotary damper 1 may be adjusted multiple times even during one rotation. In particular the torque required for rotating the operating member 301 is adjusted. A control device 302 is provided for adjusting the damper 1.

LIST OF REFERENCE NUMERALS

-   1 rotary damper -   2 component -   3 component -   3 a cover -   4 pivot shaft -   4 a engaging dog -   5 magnetorheological medium -   6 damping gap -   7 magnetic field generating device -   8 electric coil -   9 axle, axis -   10 damper device -   11 sealing device -   12 inside component -   13 outside component -   14 connecting line -   15 reservoir -   16 axial length -   17 rotary encoder -   18 winding -   19 end of 21, 22 -   20 spring device -   21 arm -   22 arm -   23 arm -   24 pole -   25 pole -   26 radial height of 6 -   27 diameter of 6 -   28 chamber -   29 separator -   30 housing -   31 end of 4 -   32 end of 4 -   33 permanent magnet -   34 cover -   35 hollow space, filler -   36 field line -   37 bearing -   38 spacer sleeve -   60 operating pedal -   100 apparatus -   112 prosthesis -   200 central control -   201 computer -   202 current/torque regulation -   203 system information -   204 actuator signal -   205 control voltage -   206 decentralized control -   300 training apparatus -   301 operating member -   302 control device 

1-26.
 27. A rotary damper for damping a pivoting motion, comprising: two components, including an inside component and an outside component radially surrounding the inside component at least in sections; said two components being disposed to form an annular and circumferential damping gap therebetween, with said damping gap being bordered radially inwardly by said inside component and radially outwardly by said outside component; a magnetorheological medium at least partly filling said damping gap and to be exposed in said damping gap to a magnetic field for damping a rotary motion between the two contrapivoting components around an axle; a plurality of at least partially radially extending arms disposed on at least one of said two components; an electric coil having at least one winding disposed on at least part of said arms, each of said windings extending adjacent to, and spaced apart from, said axle.
 28. The rotary damper according to claim 27 wherein said two components are pivotable relative to one another only by a limited pivoting angle.
 29. The rotary damper according to claim 27 wherein the damping gap is formed by a chamber, and wherein the chamber is sealed by said two components and by a sealing device disposed between said two components or by two sealing devices disposed between said two components.
 30. The rotary damper according to claim 29 wherein said chamber is radially disposed between said first component and said second component over an axial length thereof.
 31. The rotary damper according to claim 27 wherein said damping gap has a radial height of less than 2% of a diameter of said damping gap.
 32. The rotary damper according to claim 27 wherein said damping gap has a volume of less than 10 ml.
 33. The rotary damper according to claim 27 wherein said inside component comprises radially extending arms on which said electric coils are disposed.
 34. The rotary damper according to claim 27 wherein said electric coils are connected through electric connecting lines that are routed outwardly inside or outside said inside component.
 35. The rotary damper according to claim 27 wherein the adjacent ends of adjacent arms of at least one component are provided with opposite poles of the magnetic field generating devices.
 36. The rotary damper according to claim 27 wherein said outside component is part of a housing on which said inside component is accommodated, and wherein a pivot shaft of said inside component is routed outwardly out of said outside component.
 37. The rotary damper according to claim 36 wherein one end of said pivot shaft is routed out of said housing and an opposite end of said pivot shaft terminates within said housing.
 38. The rotary damper according to claim 27 which comprises a suspension device configured for building up a counterforce or a counter torque in the case of a deflection of said two components in at least one direction.
 39. The rotary damper according to claim 27 wherein said damping gap is one of a multitude of damping gaps distributed over a circumference of said components.
 40. The rotary damper according to claim 27 wherein said damping gap is fluidically connected with at least one reservoir for a magnetorheological medium.
 41. The rotary damper according to claim 27 wherein a permanent magnet is assigned to at least one electric coil.
 42. The rotary damper according to claim 27 wherein a length of said damping gap is greater than a diameter thereof.
 43. An apparatus, comprising at least one rotary damper according to claim
 27. 44. The apparatus according to claim 43 wherein a linear movement is damped by a damping device having said rotary damper.
 45. The apparatus according to claim 43 wherein a damping force or a damping torque can be adaptively varied by a damping device having a rotary damper during one single actuation.
 46. The apparatus according to claim 43, configured as a training apparatus for controlled muscular activities, comprising at least one at least partially muscular energy-operated operating member wherein the rotary damper is configured to damp at least one movement of the operating member, and further comprising at least one control device configured to register at least one characteristic quantity of a movement of the operating member and in dependence on the characteristic quantity to intentionally set and adjust the rotary damper taking into account at least one parameter. 